A stunning report in Spain’s Sport newspaper on Monday morning claimed United are ready to pay the Brazilian forward’s €200m (£172m) release clause.
However, Mourinho insisted it would be “absurd” to expect the United board to spend such an amount on one player.
"It's speculation. I always try to be objective and pragmatic with clubs and to ask them what they can give me. To ask for Neymar is absurd," Mourinho told ESPN Brazil.
Neymar has flourished this year and has provided 23 assists on top of scoring 14 goals for Barcelona this season.
The Brazilian was integral to Barcelona’s stunning comeback against PSG in the Champions League, and is widely tipped as the heir to Lionel Messi’s throne at the Catalan club.
Read the full article on eurosport.co.uk: Neymar to Man Utd is ‘impossible and absurd’ – Mourinho